Apparatus for preventing the accumulation of ice



- y 1943- M. R. BELL ETAL 2,319,968

APPARATUSFOR PREVENTING THE ACCUMULA'I 'ION OF ICE Filed Aug. 5, '1940721/520 E-Ee/Z 5535/55 5-5Z'bbzrzs ?atented May 25, 1943 UNITED." STATESPATENT OFFICE APPARATUS FOR PREVENTING THE ACCU- MULATION OF ICE MillardR. Bell, Cuyahoga Falls, and Charles S. Stebbins, Akron, Ohio, assignorsto The B. F. Goodrich Company, New York, N. Y., a corporation of NewYork Application August 3, 1940, Serial No. 350,488 6 Claims.(01244-134) grally with the sheets I! and I3 by vulcanization. The upperand lower margins of the sheets are preferably reinforced by means ofstrip fabric I6 to which the cover sheets I2 and ii are secured andthese margins are secured to the wing skin as by means of screws H, ilextending through apertures in the margins into hollow rivets l8, l8mounted in the skin.

Upon distension of the shoe in its inflated condition the area betweenthe tubes ll, l5 and the attaching margins is subjected to considerableThese and further objects will be apparent from the followingdescription, reference being bad to the accompanying drawing in which:

Fig. 1 is a plan view of a wing tip having an iceremoving shoe mountedupon its leading edge, which shoe is constructed in accordance with andembodies the invention.

Fig. 2 is a section taken along the line 2-2 of Fig. 1.

Fig. 3 is a perspective view of a portion of the structure of Fig. 2,the parts being shown in stepped relation for clarity of illustration.

Fig. 4 is' a view like Fig. 3, but showing a modifled construction.-

Fig. 5-is a view like Fig. 3, but showing a still further modifiedconstruction.

To the end of providing for a stretehablearea of the shoe between itsmargin of attachment and the region of its inflatable elements, there isprovided means, preferably in the form of a sponge rubber body orbodies, in such stretchable area and so associated with the shoe thatstretching is effected without altering the surface shape of the shoe orthe thickness thereof, so thatthe surface remains in its most effectivecondition aerodynamically, whether the shoe is in a condition of rest oris distended in operation.

The sponge rubber body, by virtue of the resilience thereof, has afurther advantage in being effective to cushion the shocks of impactfrom hail, stones or other material striking the surface. In some casesit will be desirable to extend the sponge rubber body to occupy a largepart of the area of the covering. a

The invention, according to the embodiment of Figs. 1, 2 and 3 isillustrated as applied to an inflatable shoe l0 mounted upon the leadingedge of the wing ii of an aircraft. The shoe l0 comprises an elasticbody ofrubber or rubber-like material comprising an outer elastic sheetl2, and an inner elastic sheet l3, between which sheets in the centralregion thereof are disposed infiatable tubes I4 and I5 preferably unitedinte- I face of the cover I! overlying this' 'junbtio;

the other margin of the sponge rubber bodyYIQ stretch upon beingpulledaway from the wing. It isdesirable, of course, not to hinder suchstretchability. At the sametime it is desirable to maintain a uniformthickness of the shoe throughout its extent including such stretch areaso that it will maintain an even surface. These purposes areaccomplished in accordance. with the .present invention by provision insuch stretch area of a body I! of bulky but light, resilientmaterial,preferably sponge rubber. The body is of spongerubber may be built intothe-shoe in the manner of Fig. 3 by assembling it between the coversheets l2, [3, preferably with layers of cement 20, 2| adhering the bodyl9 to such cover layers. Provision is made for tying the sponge rubberbody at its margins to the adjacent parts of the shoe, a fillet 22 ofrubber being provided there may be provided a strip 23 of rubberpreferably inset. in the sponge rubber bodyis as shown and positioned inadhesive contact-with the end surface of the rubberized fabric strip 16to resist separation at this juncture and provide a smooth and flushsurface of thecover I2 thereover. For additionally strengthening thejuncture of the body I! with the rubberized fabric IS, a strip 24 ofrubberized fabric may be provided at the end surface of the body I!between the latter and the under sheet l3 and overlying such juncture.

All the parts of the shoe i2 preferably are united integrally byvulcanization. The cover sheet I2 preferably terminates short of theultimate margin as shown to provide space for fairing strips 25, 25 inflush relation, which fairing strips are held in place by the marginalsecuring screws A shoe constructed in accordance with the foregoing hasthe advantage of maintaining a constant thickness throughout its extentupon the leading edge of the wing and provide the desired aerodynamicsurface. Also, when the 38. The shoe may to a position such as thatindicated by the broken lines 26 (Fig. 2) the stretchable area referredto is not hindered from performing its stretchin function and thesurface throughout thi area is 'distended in a smooth and regular mannerso that aerodynamic drag is minimized.

In the embodiment of Fig. 4 a sponge rubber body an is secured to a wingsurface 3i as by means of'a layer of adhesive 32, this sponge rubberbody 30 being located within the stretch area of a shoe 33 comprisingupper and lower elastic cover sheets 34 and 35 respectively. inflatabletubes 36, 31, and a reinforced attaching margin be set within a recessin the leading edge of the wing which recess terminates in a shoulder39. The reinforced margin 38 is attached to the wing skin by means ofscrews 40 extending through the margin and such screws may be used alsoto hold a fairing strip H in place in a manner to provide a flushsurface at the shoulder 39.

In the embodiment of Fig. 4 the body 30 of sponge rubber is not attacheddirectly to the shoe 33, but is adhered only to the underlyingwing-surface, the elastic shoe upon forward distension being adapted toslide over the sponge rubber body 30 and even to extend away fromcontact with the same during such distension. The body of sponge rubber30, however, serves to fill out the space in such stretch area toprovide a uniform thickness of the shoe when mounted in place and asmooth aerodynamic outer surface of such shoe. 3

In the embodiment of differs from that of Fig. 4 in that a sponge rubberbody is secured, not to the wing skin, but to the distensible shoe 5|,at the under surface thereof in its stretched region. The shoe maycomprise upper and lower elastic sheets 52, 53, an intermediateinflatable element 54 anda reinforced margin 55 whichmay be attached tothe wing skin by means of screws 56 in the manner hereinbeforeexplained, which screws may serve also to hold a fairing strip 51 inplace.

The' body 50 of sponge rubber is adhered to the under surface of thelower elastic sheet 53 and provides the uniform thickness of the shoe byfilling out the stretch area thereof. Upon distension of the shoe wheninflated, the sponge rubber body 50, being stretchable and resilient, iscapable of stretching along with the cover sheets in the stretch area soas not to hamper the distending function of the shoe and when the shoerecovers from its distension the sponge rubber Fig. 5 the constructionbody returns to the normal, unstretched shape shown. Variations may bemade without departing from the scope of the claimed.

invention as it is hereinafter We claim:

ice comprising inner and outer extensible sheets. mean for attaching thesame to a surface along a zone thereof, an inflatable elementincorporated with said sheets in a portion spaced from the attachingzone by a stretchable area of said sheets, and a body of sponge rubberincorporated with the elastic sheets in said stretchable area in amanner providing a substantially uniform thickness of the structure suchas to provide a flush and even outer surface thereof.

2. Means for preventing the accumulation of ice as defined in claim 1,in which the said body of sponge rubber is disposed between said elasticsheets and secured thereto in the said extensible area thereof.

3. Means for preventing the as defined in claim 1 in which the body ofsponge rubber is mounted between the under elastic sheet and the surfaceof the aircraft.

- 4. A protective covering for aircraft comprising an extensible surfacelayer having an attaching portion, an inflatable portion spacedtherefrom and an intervening stretchable portion, and a filler elementof resilient sponge rubber material substantially coextensive with saidstretchable portion and disposed beneath the surface thereof providing anormal thickness of said stretchable portion such that its outer surfaceis substantially flush and even with the adJoining surface of saidinflatable portion when the covering i mounted upon the aircraft.

5. A protective covering for aircraft comprising an extensible layerhaving an attaching portion, anlnflatable portion spaced therefrom andaccumulation of ice an intervening stretchable portion, and a flllerelement of resilient sponge rubber material united with adjacentmaterial ofthe covering and dissuch that its outer surface issubstantially flush and even with the adjoining surface of saidinflatable portion when the covering is mounted upon the aircraft.

6. A protective covering for aircraft comprising an extensible surfacelayer having an attaching portion, an inflatable portion spacedtherefrom and an intervening stretchable portion, and a filler elementof resilient sponge rubber material united with said layer at saidstretchable portion beneath the surface thereof providing a normalthickness of said stretchable portion such that its outer surface issubstantially flush and even with the adjoining surface of saidinflatable portion when the covering is mounted upon the

